v. t. [ L. circumvallatus, p. p. of circumvallare to surround with a wall; circum + vallare to wall, fr. vallum rampart. ] To surround with a rampart or wall. Johnson. [ 1913 Webster ]

a. 1. Surrounded with a wall; inclosed with a rampart. [ 1913 Webster ]

2. (Anat.) Surrounded by a ridge or elevation; as, the circumvallate papillæ, near the base of the tongue. [ 1913 Webster ]